Universal Suffrage is dead to me. Nice try, doesn't work. If that means my own ability to vote is removed, so be it. Some people, I'm afraid, shouldn't vote. There is scope for a 'voter licence', which is opt-in, like a drivers licence, involving a fairly basic civics test.
I contend that 25 is a reasonable age to start voting. Minds and bodies are developed to adult level (mostly), and people will generally have some work experience.
Should we exclude the unemployed? I contend that anyone unemployed over three years should be excluded, as non tax-payers. Anyone temporarily unemployed (been there) is likely just going through a tough time, not excluded.
I would exclude housewives (and househusbands) who are not contributing tax. Those working part-time, they get to vote. Pensioners, with some reservation, I would accept have enough of a stake, built up over a lifetime, to retain their voter rights. One hopes that they have built up a reservoir of experience, even if they are no longer 'in the game' of working and paying tax. This could be under review every five years.
Oh, and minimum ten years citizenship required. Boomers, obviously, will never get to vote in any election whatsoever, and should consider themselves fortunate we don't force them do undergo yearly shame walks.
Any change has consequences. Any technology is dual use. Quite what the consequences are, I clearly can't divine. Politicians frame their manipulations to the voter, if the voter changes, thus do the manipulations. Likely the turn would be towards a small government, low-tax society, as tax payers exert their power. Logically, this will have consequences on the welfare state, and the health service particularly. I'd assume enhanced private sector involvement, again a dual use technology. Immigration would essentially return to zero, as poll after poll shows that immigration is hugely unpopular among the native citizenry. Lastly, we would likely have the death penalty.
In other words, in almost every policy area, we would have precisely the opposite of that to we are currently subjected. Would this be a harder, more brutal world, with many simply left on the sidelines, to live in Victorian squalor? Would the economy collapse entirely? Again I concede, this is not something I can possibly know. I do know that sixteen year olds should never vote, as Greta Thunberg proves daily.